Sputtering apparatuses are widely used in the manufacture of optical disks, in the manufacture of electronic devices such as liquid crystal display elements and semiconductor elements, and further, in the formation of metal thin films and insulator thin films in general. In the sputtering apparatus, a raw material for thin film formation is used as a target, while plasma based on an argon gas or the like is caused to occur by supply of DC high voltage or high-frequency power. The target by the plasma caused to occur from gas is activated to be melted and scattered on a substrate to be processed to form a film on the substrate.
In a sputtering film forming method, a recent tendency has been predominantly directed to a film forming method that uses a magnetron sputtering apparatus which can raise the film forming rate. To this end, the magnetron sputtering apparatus is structured such that magnets are disposed on the back side of a target to generate the lines of magnetic force parallel to a target surface, thereby confining plasma to the target surface to obtain high-density plasma.
For the purpose of improving the target utilization efficiency to reduce the production cost and enabling stable long-term operation, the inventors have proposed a rotary magnet sputtering apparatus. This rotary magnet sputtering apparatus is structured such that a plurality of plate-like magnets are continuously disposed on a columnar rotary shaft and, by rotating them, a magnetic field pattern on a target surface moves with time. The rotary magnet sputtering is excellent not only in significant improvement of the utilization efficiency of a target material but also in prevention of charge-up damage and ion irradiation damage due to plasma (see Patent Document 1).    Patent Document 1: PCT International Publication No. WO2007/043476